This core will provide Projects I, II, and III with the capability to identify viral respiratory pathogens related to both the inception and exacerbation of childhood asthma. The core facility will be located at the Wisconsin State Laboratory of Hygiene (WSLH) which is located on the University of Wisconsin-Madison campus. The WSLH has provided all of the viral diagnostic support for the COAST project and thus far has processed more than 2500 nasal lavage samples. This core will be responsible for culture and direct immunofluorescence testing and the implementation and application of PCR technology to increase the sensitivity of viral diagnosis in support of Project I. In addition,, this core will be responsible for the production of virus stocks and the performance of virus titrations in support of Projects II and III. The latter work will be performed at the Morris Institute of Respiratory Research located in K4/9 of the Clinical Science Center at the University of Wisconsin.